1. Field of the Invention
The present invention generally relates to the remote control of an apparatus, and more particularly, to a remote control system including a controlling apparatus and an apparatus controlled by the controlling apparatus that ensures an operation request to be communicated with the controlling apparatus. The present invention also relates to a method of remote controlling an apparatus.
2. Description of the Related Art
Various remote control systems are proposed. For example, Japanese Patent Laid-Open Application No. 2004-30625 discloses a remote control system in which a controlling apparatus disposed in a service center (control center) controls various apparatuses disposed in a user's office, for example, via a network such as the Internet. An example of the apparatuses controlled by the controlling apparatus includes an image processing device such as a printer, a facsimile machine, a digital copier, and a digital multifunctional apparatus, and an image processing apparatus such as a scanner. A remote control system is further proposed in which, if a controlled apparatus does not have communication capability, an intermediate apparatus (remote control intermediate apparatus) is connected to the controlled apparatus, and the controlling apparatus controls the controlled apparatus via the network and the intermediate apparatus.
Various communication systems including multiple communication apparatuses connected via a network are practically used in which a communication apparatus sends a command requesting another communication apparatus to perform an operation, and the another communication apparatus returns the result of the operation to the communication apparatus. For example, Japanese Patent Laid-Open Application No. 2001-273211 discloses a communication system in which a remote processor transmits a message to a local processor, the message including a command that the local processor is requested to perform, and receives a response to the command from the local processor.
The above application further discloses a technique in which, if the local processor is inside fire wall, the local processor transmits a request for the transmission of a command to the remote processor outside the fire wall, and receives a command from the remote processor through the firewall as a response to the request.
Whether the controlling apparatus in the service center can communicate with the controlled apparatus or the intermediate apparatus depends on the network environment of a user site. A proxy server (fire wall) is usually provided to protect the controlled apparatus and the intermediate apparatus outside the fire wall from unauthorized access from an exterior apparatus. In this case, the controlled apparatus and the intermediate apparatus need to be set with correct parameters such as the IP address, log-in name, log-in password of the proxy server, and the URL of the center.
However, if these parameters are not set correctly, or the proxy server is not in operation due to power failure, for example, the request from the controlled apparatus or the intermediate apparatus communicated using Hyper Text Transfer Protocol (HTTP) may not reach the controlling apparatus.
If authorization information required for the communication of the intermediate apparatus is damaged, the communication may fail.
Furthermore, in the case in which the LAN (network) cable is unplugged, or the case in which the intermediate apparatus is turned off and not in operation, the request from the controlled apparatus or the intermediate apparatus may not reach the controlling apparatus.
If the communication fails, the controlling apparatus can not obtain information of the controlled apparatus or the intermediate apparatus, and the controlled apparatus and the intermediate apparatus can not make a call (message indicating abnormality) to the controlling apparatus.